Some file I edit create large temporary files when encoding the file to DVD ready format that are way bigger than the original files, so I would safely say.. a lot! Capturing 2 hours in DVD quality can run up to 7 gigs.. You can capture with less quality, but you'll have lees room to play with quality. Then, once captured, I guess trhat you'll have to do a bit of editing. Then you'll play with the same file and create another one that will add to the original, because you wont delete the original captured file unless you are sure that you edit it the right way first. Then when creating the DVD, you'll will create an image first that will take a lot of room too.. so, do yourself a favor... if you have a lot of tape to do, get at least 120 gigs, if you can afford. because, you will often have to capture 2 or 3 movies, then edit and create the DVD. I play with a 100 gigs partition and I dont always have to clear old project too soon to have room ... And having lot of room improve recording and editing, because you wont have to defrag as often to get uncut space on your HDD... having the file cut in many segments because there is not enough linear space to have it in one continuous segment might cause dropped frame and jerky editing.
512 megs of ram will do, but 1 gigs is better..
-Always put the blame on you first, then on the hardware !!!